    /*****页首导航*****/
    a {
      text-decoration: none;
    }
    
    a:hover {
      text-decoration: underline;
    }
    
    ul#navWrapper {
      border: 1px black dashed;
      margin-left: -41px;
    }
        
    ul#navWrapper li {
      border: 1px red dashed;    
      float: left;
      list-style: none;
      margin-right: 0.5em;
      background-color: #DDD;
      padding: 0 0.25em;
    }
    
    ul#navWrapper li li {
      border: 1px blue dashed;    
      float: none;
      margin-left: -44px;
      margin-top: 3px;
    }

    ul#navWrapper li li:first-child { 
      margin-top: 4px;
    }

    ul#navWrapper ul {
      width:60px;     /*二级栏目固定宽度*/
      display: none;
      position: absolute;
    }
    
    ul#navWrapper li:hover > ul {
      display: block;
    }

    ul#navWrapper ul ul{
      display: none;
      position: absolute;
      left:100px;
      top:0px;
    }
    
    ul#navWrapper ul li:hover ul {
      display: block;
    }
    /**********/
    
    div#content {
      border: 1px green dashed;    
      clear: both;
    }